#!/usr/bin/env node
import path from "node:path";
import { pathToFileURL } from "node:url";

const LOOPBACK_HOSTS = new Set(["127.0.0.1", "localhost", "::1", "[::1]"]);

export function validateLoopbackHttpUrl(input) {
  let url;
  try {
    url = new URL(String(input ?? ""));
  } catch {
    throw new Error("base_url_invalid");
  }

  if (url.protocol !== "http:") throw new Error("base_url_protocol_not_http");
  if (url.username || url.password) throw new Error("base_url_credentials_forbidden");
  if (!LOOPBACK_HOSTS.has(url.hostname)) throw new Error("base_url_host_not_loopback");
  if ((url.pathname && url.pathname !== "/") || url.search || url.hash) {
    throw new Error("base_url_must_be_origin_only");
  }

  return url.origin;
}

export function validateTcpPort(input) {
  const raw = String(input ?? "");
  if (!/^[1-9][0-9]{0,4}$/u.test(raw)) throw new Error("port_invalid");
  const port = Number(raw);
  if (!Number.isSafeInteger(port) || port > 65535) throw new Error("port_out_of_range");
  return String(port);
}

if (process.argv[1] && import.meta.url === pathToFileURL(path.resolve(process.argv[1])).href) {
  try {
    console.log(
      process.argv[2] === "--port"
        ? validateTcpPort(process.argv[3])
        : validateLoopbackHttpUrl(process.argv[2]),
    );
  } catch (error) {
    console.error(`[local-candidate][ERROR] ${error instanceof Error ? error.message : String(error)}`);
    process.exit(1);
  }
}